A linear guide as this kind of a motion guide device includes a track rail attached to a fixing portion and a movable block fixed to a movable portion. The movable block is assembled onto the track rail in a linearly movable manner. Between the track rail and the movable block, a plurality of balls is rollably interposed in order to reduce frictional resistance. On the movable block, an endless circulating path is arranged for circulating the balls. The endless circulating path of the linear guide is formed with a loaded ball rolling path arranged between a ball rolling groove of the track rail and a loaded ball rolling groove of the movable block, an unloaded ball rolling path that is parallel to the loaded ball rolling path, and a pair of U-shaped direction change paths each connecting the loaded ball rolling path and the unloaded ball rolling path (e.g., see Patent Literature 1 shown below).
The pair of direction change paths is arranged on lid members on both end sides in a moving direction of the movable block, and the direction change paths are each formed in a combination of an end plate having a direction change portion on an outer peripheral side and an R piece fitted into the end plate as a direction change portion on an inner peripheral side. In other words, the linear guide is formed by using the end plate not only as the lid members, but also as part of direction change paths.